Геометрия контуров капельного увлажнения почв

Abstract

Purpose: to determine dependencies and develop a methodology for calculating the geometric dimensions and constructing the outline of local moisture contours formed in the soil space during drip irrigation. Materials and methods. The factual basis of the development was the data of full-scale (field) measurements of the contours of the drip-moistened soil space and their office processing. The studies were carried out on experimental sites with different soil cover, represented by steppe, dry steppe and steppe-desert soil types: chernozems (ordinary and southern) and chestnut soils with a wide range of granulometric texture, water-physical properties and with different levels of pre-irrigation moisture, when ir-rigated with emitters productivity from 1,0 to 6,0 l/h. Results and discussion. During the study, the following things were considered as determining the process of contour formation and the contour geometry: soil conditions characterized by the physical clay content, the min-imum water capacity, bulk density and the level of pre-irrigation moisture; technological pa-rameters determined by the level of post-irrigation moisture, the given depth of soil moisture, the flow rate of drip micro-water outlets and the volume of water supply. Empirical depend-ences that allow determination of the linear dimensions, the wetted area dimensions and the volumes of moisture contours are obtained according to the given values: the physical clay content in soil within 18.0–77.0 % of the dry soil mass (DSM), the lowest moisture capacity in the range 16.5–32 % DSM, wetting depth from 0.5 to 1.2 m, additional irrigation moisture from 60 to 80 % of the level of the minimum water capacity, emitter flow from 1.0 to 6.0 l/h. Conclusion. A system of empirical dependencies has been obtained, and methods for predict-ing the external shape, linear, areal and volumetric dimensions of local moisture contours formed in the soil space during drip irrigation have been developed.